The Hybridoma Core Facility will be used by approximately 30 UM- RDCC investigators who are pursuing a variety of research projects that require monoclonal antibodies. The primary purpose of the Hybridoma Core is to generate somatic-cell hybrids (hybridomas) that produce monoclonal antibodies of desired specificity. It is currently supported by the Michigan Diabetes Research and Training Center (MDRTC), and by the University of Michigan Multipurpose Arthritis Center (UM-MAC), for use by investigators within these centers, t a 20% recharge. It is also used by other investigators on a full recharge basis. Services provided include immunization of mice, fusion of B lymphocytes with myeloma cells to create hybridomas, subcloning and cryopreservation of hybridomas, antibody isotyping production of ascites in mice, and production of antibodies in vitro. Consultation is provided from the Hybridoma Core directors in design of immunization strategies and screening assays to ensure efficient generation and detection of the desired monoclonal strategies and screening to ensure efficient generation and detection of the desired monoclonal antibodies. The majority of hybridomas produced in the core are of murine origin, but rat, hamster and human hybridomas have also been produced. Since its establishment in 1980 the Hybridoma Facility has produced monoclonal antibodies against a wide variety of lymphocyte surface antigens, tumor cell antigens, tumor cell antigens, purified proteins, cytokines, hormones, hormone receptors and recombinant proteins. Over the past thirteen years of UM-CAS support (1988-2000) more than 200 fusions were performed for UM-MAC investigators. Subcloning was performed in more than 1000 hybridomas, and more than 1000 monoclonal antibody batches were produced in murine ascites. A variety of specialized procedures have been added during the current funding cycle to address various needs of UM-MAC investigators, and future UM-RDCC investigators. The current proposal will allow this faculty to continue to provide up-to- date hybridoma technology for UM-RDCC laboratories. The core will also provide collaborative and consultative services for the UM-RDCC investigators who may wish to select recombinant antibody-like reagents from phage display libraries. Through these initiatives, the Hybridoma Core will remain on the cutting edge of monoclonal antibody technology, and continued to provide optimal service to a broad range of users.